scholarly journals On chemical reaction in the electric discharge. I—The chemical effects of impulse discharges

1935 ◽  
Vol 152 (875) ◽  
pp. 158-171 ◽  
Keyword(s):  
Chemical Reaction ◽  
Electric Discharge ◽  
Discharge Tube ◽  
Atomic Hydrogen ◽  
Electric Discharges ◽  
Active Nitrogen ◽  
Atom Concentration ◽  
Chemical Effects ◽  
Spark Gap ◽  
In Series

Although a very large number of studies has been made upon the chemical reactions which can be induced by electric discharges, the effects of controlled condenser sparks appear to have been neglected, with one exception. Wrede has shown that if a large condenser (8 mfd) is charged to a high potential, and then allowed to discharge through a gas at low pressure, a spark gap being inserted in series with the discharge tube proper to increase the breakdown voltage, then hydrogen, oxygen, and nitrogen may be dissociated to the extent of 80, 60, and 40% respectively, the atom concentration being measured upon a most ingenious “diffusion gauge.” The Wrede discharge has been extensively employed by Steiner and his associates in a series of semi-spectroscopic investigations upon active nitrogen and atomic hydrogen, but its use as a means of effecting chemical reaction has not so far received attention.

Reaction of atomic hydrogen with tetrafluoroethene

1969 ◽  
Vol 47 (10) ◽  
pp. 1696-1698
Author(s):  
Lei Teng ◽  
W. E. Jones
Keyword(s):  
Electric Discharge ◽  
Discharge Tube ◽  
Atomic Hydrogen ◽  
Hydrogen Atoms

Hydrogen atoms, generated in a Wood's electric discharge tube, were allowed to react with tetrafluoroethene. The products of the reaction were found to be HF, C2F3H, C2H2, C2F2H2, C2F4H2, C2FH3, C2H4, and CHF3. The formation of the products with the exception of HF was studied quantitatively from 30–330 °C.

scholarly journals On the excitation of the band spectrum of helium

1925 ◽  
Vol 109 (750) ◽  
pp. 267-272 ◽  
Keyword(s):  
Discharge Tube ◽  
High Current Density ◽  
Band Spectrum ◽  
Essential Condition ◽  
Spark Gap ◽  
In Series ◽  
Pure Helium ◽  
Faint Band ◽  
The Individual ◽  
Low Pressures

It is now generally agreed that the band spectrum of helium, which was first observed by Curtis (‘Roy. Soc. Proc.,’ A, vol. 89, p. 146, 1913) and by Goldstein (‘Verh. d. Deutsch. Phys. Gesell.,’ vol. 15, p. 402, 1913), is to be attributed to some molecule of helium. This band spectrum is peculiar in the fact that the heads of the bands have been shown by Fowler (‘Rov. Soc. Proc.,’ A, vol. 91, p. 208, 1915) to follow the law usually associated with line spectra, though the individual lines composing the bands can be represented by the parabolic arrangement appropriate to band series. More recently, Curtis has carried out a series of investigations (‘Roy. Soc. Proc.’) on the structure of the bands in terms of the quantum theory. Attention may here be drawn to two peculiarities in the spectrum. There is one isolated band with a head at about λ = 5733 A., which is degraded to the violet, whilst all the remaining bands are degraded to the red. Also Goldstein ( loc. cit. ) observed a number of faint band lines in the region about λ = 5390 A. to λ = 5270 A., which were not recorded in Curtis’s paper ( loc. cit .). It is well known that in vacuum tubes excited by uncondensed discharges only faint traces of the principal band heads are visible in the positive column though the complete band spectrum appears in the negative glow. The band spectrum can be excited with much greater intrinsic brightness by using a discharge tube with a wide tube in place of the usual capillary, and exciting it by means of a discharge from an induction coil or transformer, with a condenser in parallel and a small spark gap in series with the discharge tube, the band spectrum under these conditions appearing throughout the tube. There appears to be an optimum length of spark gap and the spectrum tends to become weaker when the length is increased beyond a certain point. Curtis ( loc. cit .) has found that the band spectrum is not strongly developed at low pressures, and this condition appears to be independent of other conditions of excitation. In the present investigation we have found that under certain conditions the band spectrum can be greatly modified. It was observed that when a vacuum tube, containing pure helium, which had been made with the capillary in several sections of different bore, was excited with an uncondensed discharge the narrowest section, which was of the finest thermometer tubing that could be worked conveniently in the blowpipe, showed nothing but the line spectrum, but in the wider sections on either side the band spectrum was quite strongly developed. This seems to show that a high-current density is not an essential condition for the excitation of the band spectrum, but it was remarkable that with these tubes it appeared in the wider parts, where it would not have been seen if the capillaries had not been provided with a section of narrow bore.

scholarly journals The after-luminosity of electric discharge in hydrogen, observed by Hertz

1912 ◽  
Vol 86 (590) ◽  
pp. 529-533 ◽  
Keyword(s):  
Electric Discharge ◽  
Discharge Tube ◽  
Ultra Violet ◽  
Good Evidence ◽  
Pure Hydrogen ◽  
Active Nitrogen ◽  
Explosive Action ◽  
Small Discharge

In previous papers I have examined certain striking cases of after-luminosity in gases through which the electric discharge has been passed. The cases dealt with fall under two heads, those due to ozone, and those due to active nitrogen. I wish now to pass to case in which neither of these substances is concerned. Hertz described a phenomenon of after-luminosity which he had observed in hydrogen. The method of investigation was somewhat special. A series of jar discharges was passed through a small discharge tube, with an open end, arranged inside a bell jar. It was then observed that at each discharge a stream of luminous gas was squirted from the end of the small discharge tube into the bell jar. This is apparently due to kind of explosive action of the spark—the same, probably, as that described by De La Rue and Muller. The method is well adapted to show the afterglow in other gases, nitrogen or air, for instance, but the immediate concern is with hydrogen. With this gas, Hertz sometimes observed a jet of blue luminosity, which was best developed at a pressure of 100 mm. He considered that he had good evidence that this luminosity showed the hydrogen spectrum, but be found an unaccountable capriciousness of the effect, which sometimes refused to appear at all. He did not succeed in tracing the cause of this uncertainty. Goldstein made similar experiments; he states that the spectrum consists of at least 10 bands, from the green to the ultra-violet, totally unrelated to the recognised hydrogen spectrum. But he believed that the glow was due to pure hydrogen.

scholarly journals A chemically active modification of nitrogen, produced by the electric discharge.— IV

1912 ◽  
Vol 87 (594) ◽  
pp. 179-188 ◽  
Keyword(s):  
Electric Current ◽  
Chemical Reaction ◽  
Electric Discharge ◽  
Chemical Process ◽  
Chemical Substance ◽  
Ordinary Sense ◽  
Active Nitrogen ◽  
Chemical Changes ◽  
Chemical Substances ◽  
The Moment

1. General . The properties of active nitrogen have been described throughout on the assumption that it is to be classed with other chemical substances, and that its reversion to ordinary nitrogen is to be regarded simply as a chemical reaction, as one would regard the change of ozone to oxygen, or of red to ordinary phosphorus. I see no reason to abandon this position. There are, however, some circumstances not at first sight falling in very naturally with it. One of these is the acceleration of the change by cooling, a phenomenon without parallel in any recognised reaction. Another is the development of many of the bands of the nitrogen spectrum. This spectrum has never been produced by any other purely chemical process, but (apart from active nitrogen) is only observed when an electric current is actually passing through the gas at the moment of observation. Lastly, the ionisation associated with a stream of glowing nitrogen has suggested serious doubts whether its chemical peculiarities are really due to the presence of a definite chemical substance in the ordinary sense, or to some unexplained survival of the conditions of the disruptive discharge. Evidence will he brought forward in this paper which is considered to be entirely in favour of the former alternative. 2. Energy of Active Nitrogen . These considerations have made it important to determine whether the energy emitted by active nitrogen in reverting to ordinary nitrogen is comparable with that liberated in other chemical changes. The experiments to be described answer this question in the affirmative.

scholarly journals IV. On the nature of the streamers in the electric spark

1909 ◽  
Vol 209 (441-458) ◽  
pp. 71-87 ◽  
Keyword(s):  
Incident Light ◽  
Close Relation ◽  
Actual Process ◽  
Metal Vapour ◽  
New Era ◽  
Spark Gap ◽  
In Series ◽  
The Subject ◽  
The Doppler Effect ◽  
The Individual

When the oscillating electric spark is examined in a rapidly rotating mirror, the successive oscillations render themselves evident in the image as a series of lumnious curved streamers which emanate from the poles and extend towards the centre of the spark gap. These streamers were first observed by Feddersen in 1862, but the work of Schuster and Hemsalech in 1900 may be said to have opened up a new era in the subject. These workers threw the image of the spark on the slit of a spectroscope, and photographed the resulting spectrum on a film which was maintained in rapid rotation in a direction at right angles to that of the incident light. In their photographs they found that the air lines extended straight across from pole to pole, but that the metal lines were represented by curved bands drawn out in the centre of the spark gap. There is a close relation between these bands and the streamers seen in the unanalysed inductive spark. Schuster and Hemsalech carried out their experiments with the smallest possible inductance in series with the spark, and thus made the period of the oscillations so small that the drawing out on the film was insufficient to separate the individual oscillations from each other. Thus their curved lines represent a composite structure, consisting of all the streamers due to the successive oscillations superposed on each other. It follows from their results that the light of the streamers in the spark is entirely produced by the glowing of the metallic vapour of the electrodes, and that, while the luminosity of the air is practically instantaneous in its occurrence, that due to the metal vapour occurs in the centre of the spark gap an appreciable time later than near the poles. The actual process which goes on in the spark and gives rise to this delay in the arrival of the metallic vapour at the centre of the gap is not yet thoroughly understood. Schuster and Hemsalech make the natural supposition that it is due to the fact that the metal of the electrode is vaporised and rendered incandescent by the heat of the spark, and that the vapour takes an appreciable time to diffuse from the electrodes to the centre of the gap. The exception which has been taken to this view has arisen in part from the difficulty of observing the Doppler effect on the metallic lines which should be a concomitant of the diffusion of the vapour from the poles, and in part from the extraordinary results which the authors themselves obtained in some metals for the velocity of the diffusion corresponding to the different lines. In the case of bismuth and, in a less degree, of cadmium the different metallic lines could be divided into groups of different curvatures which indicated different velocities of diffusion towards the centre of the gap. As regards the former matter, there does not seem to be involved any real difficulty to the explanation, as Dr. Schuster has himself recently shown. The curious effect of the different curvatures of the lines of the same element has, however, always remained more or less of a difficulty in the way of a complete acceptance of their view. Schuster and Hemsalech themselves refer to the possibility in the case of bismuth that the metal may be a compound, and that the two kinds of molecules give rise to the differently curved lines. Other explanations have been made by different writers, but it cannot be said that any explanation adequately supported by experiment has been forthcoming. In view of this incompleteness in our knowledge of the constitution of the streamers it seemed to me that further observations with a rotating mirror would possibly be of value, and the investigations recorded below succeed, I think, in throwing a clearer light on the nature of the streamers, and on certain other phenomena which are characteristic of the spark.

IX. On the electrolysis of gases

1895 ◽  
Vol 58 (347-352) ◽  
pp. 244-257 ◽  
Keyword(s):  
Electric Discharge ◽  
Discharge Tube ◽  
Negative Electrodes

In the experiments described in this paper I have used the spectroscope to detect the decomposition of gases by the electric discharge and the movement of the ions in opposite directions along the discharge-tube. The method consists in sending the electric discharge through a tube so arranged that the spectra close to the positive and negative electrodes can easily be compared; thus the presence or absence of certain ions at these electrodes can be ascertained.

THE REACTION OF ACTIVE NITROGEN WITH PROPYLENE

1952 ◽  
Vol 30 (12) ◽  
pp. 915-921 ◽  
Author(s):  
G. S. Trick ◽  
C. A. Winkler
Keyword(s):  
Double Bond ◽  
Nitrogen Atom ◽  
Hydrogen Cyanide ◽  
Atomic Hydrogen ◽  
Atomic Nitrogen ◽  
Active Nitrogen

The reaction of nitrogen atoms with propylene has been found to produce hydrogen cyanide and ethylene as the main products, together with smaller amounts of ethane and propane and traces of acetylene and of a C4 fraction. With excess propylene, the nitrogen atoms were completely consumed and for the reaction at 242 °C., 0.77 mole of ethylene was produced for each mole of excess propylene added. For reactions at lower temperatures, less ethylene was produced. The proposed mechanism involves formation of a complex between the nitrogen atom and the double bond of propylene, followed by decomposition to ethylene, hydrogen cyanide, and atomic hydrogen. The ethylene would then react with atomic nitrogen in a similar manner.

Chemical Effects of Atomic Hydrogen in Aqueous Solutions1

1958 ◽  
Vol 80 (17) ◽  
pp. 4487-4491 ◽  
Author(s):  
Thomas W. Davis ◽  
Sheffield Gordon ◽  
Edwin J. Hart
Keyword(s):  
Atomic Hydrogen ◽  
Chemical Effects

scholarly journals An active modification of nitrogen, produced by the electric discharge.—V

1913 ◽  
Vol 88 (605) ◽  
pp. 539-549 ◽  
Keyword(s):  
Electric Discharge ◽  
Discharge Tube ◽  
Good Condition ◽  
Gas Space ◽  
Commercial Nitrogen

Experience has led to certain modifications of detail in preparing nitrogen for the experiments. Commercial nitrogen from cylinders is still used, but instead of passing it over phosphorus it is allowed to stand in contact with it for some hours. The former method does well enough when the phosphorus is freshly cut, but in time the surface deteriorates, owing, in part at least, to the accumulation of oxides of phosphorus, which tend to obstruct access of the gas. Two 15-litre aspirator bottles are arranged as a gasholder in the usual way, the gas being displaced by water. In the gas space is hung up a muslin bag containing chopped phosphorus. On filling the gasholder with commercial nitrogen the phosphorus fumes freely, and all traces of oxygen are removed in the course of two or three hours. The fumes subside, and the gas is ready for use. It merely requires drying on its way to the discharge tube. This 15-litre supply is more than enough for most experiments. When it is used up the water rises and drowns the bag of phosphorus, dissolving out the oxides which have been formed, and leaving it in good condition for use next time.

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